Yeast represented by Saccharomyces cerevisiae is widely used in the food industry by making use of its fermentation capacity and as a host for production of a variety of substances. In addition, yeast is a major study subject in the field of genetic engineering. As an example of yeast, yeast (also referred to as thermotolerant yeast) for which the optimal temperature range falls within a relatively high temperature range is known, as well as Saccharomyces cerevisiae. 
A reaction system can be maintained within a relatively high temperature range using such thermotolerant yeast, making it possible to prevent contamination. In addition, it is necessary to culture yeast in a relatively high temperature range depending on the type of substance to be produced or reaction system. In such case, it is particularly preferable to use thermotolerant yeast.
As an aside, in general, when a given gene is expressed in yeast, a promoter that constantly allows high expression is used. Examples of known promoters that can be used in yeast include a TDH3 promoter, an ADH1 promoter, and a TEF1 promoter. In addition, Non-Patent Literature 1 discloses that a cellulase gene was expressed in thermotolerant yeast using a TDH3 promoter.
Although the above different promoters can constantly cause high expression of genes located downstream thereof in generally available yeast such as Saccharomyces cerevisiae, the expression levels of such downstream genes are insufficient when thermotolerant yeast is used as a host. That is, there is no conventionally known promoter that can cause high expression of a desired gene in thermotolerant yeast.